package com.atguigu.gulimall.product.service.impl;

import org.springframework.stereotype.Service;

import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;

import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.atguigu.common.utils.PageUtils;
import com.atguigu.common.utils.Query;

import com.atguigu.gulimall.product.dao.CategoryDao;
import com.atguigu.gulimall.product.entity.CategoryEntity;
import com.atguigu.gulimall.product.service.CategoryService;


@Service("categoryService")
public class CategoryServiceImpl extends ServiceImpl<CategoryDao, CategoryEntity> implements CategoryService {

    @Override
    public PageUtils queryPage(Map<String, Object> params) {
        IPage<CategoryEntity> page = this.page(
                new Query<CategoryEntity>().getPage(params),
                new QueryWrapper<CategoryEntity>()
        );

        return new PageUtils(page);
    }

    @Override
    public List<CategoryEntity> listWithTree() {
        //查出所有分类
        List<CategoryEntity> entities = baseMapper.selectList(null);
        //组装成树形结构
        List<CategoryEntity> levelMenus= entities.stream().filter(categoryEntity ->
             //查找所有的父类
             categoryEntity.getParentCid() == 0
        ).map(menu ->{
            //查找父类下对应的子类信息
            menu.setChildren(getChildrens(menu,entities));
            return menu;
        }).sorted((menu1,menu2)->{
            //排序
            return (null == menu1.getSort() ? 0:menu1.getSort()) - (null == menu2.getSort() ? 0:menu2.getSort());
        }).collect(Collectors.toList());
        return levelMenus;
    }

    //递归查找
    private  List<CategoryEntity> getChildrens(CategoryEntity root,List<CategoryEntity> all) {
        List<CategoryEntity> children = all.stream().filter(categoryEntity->{
            return categoryEntity.getParentCid() == root.getCatId();
        }).map(categoryEntity ->{
            //递归再次查找子菜单
            categoryEntity.setChildren(getChildrens(categoryEntity,all));
            return categoryEntity;
        }).sorted((menu1,menu2)->{
            //菜单排序
            return (null == menu1.getSort() ? 0:menu1.getSort()) - (null == menu2.getSort() ? 0:menu2.getSort());
        }).collect(Collectors.toList());
       return children;
    }

}